Box panel stiffener for wall panel system



FIG. 1 is a perspective view of a box panel stiffener for wall panel system, showing our new design;

FIG. 2 is a front elevation view thereof.

FIG. 3 is a rear elevation view thereof.

FIG. 4 is a left side elevation view thereof.

FIG. 5 is a right side elevation view thereof.

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The article is shown with a symbolic break in its length. The appearance of any portion of the article between the break lines forms no part of the claimed design. 

CLAIM We claim the ornamental design for a box panel stiffener for wall panel system, as shown and described. 